In Web search, a key early contribution was from [1]}, describing a taxonomy of Web search queries: Navigational, informational, and transactional. Looking at log traces of the AltaVista search engine, an earlier paper had already listed “yahoo” is one of the most common queries [2]}. Broder was also using AltaVista logs, and may have noticed that the clicks for that query were overwhelmingly on yahoo.com, indicating an intent to navigate to a specific site. This observation, of the queries and preferred responses of real users, would be an example of user understanding by behavior log observation (Table REF ).
